The Prophet (ﷺ) said: “The deen is naseehah.” This comprehensive word refers to the importance of naseehah in Islam. It is the foundation and the pillar of the Deen. It is also part of Hadith of Jibreel, of which the Prophet (ﷺ) explained about Islam, Iman and Ihsan, where he named them as deen, as he (ﷺ) said: “This is Jibreel, he came to teach you your deen.” This kind of statement is similar to he’s saying (ﷺ): “Al-Hajj is ‘Arafah,” that is because the Wuquf in ‘Arafah is the greatest pillar of Hajj, of which there is no Hajj for the one who misses it.

This comprehensive word refers to the importance of naseehah in Islam. It is the foundation and the pillar of the Deen.

In Mustakhraj Abi ‘Awanah, the Prophet (ﷺ) repeated the sentence “ad-Deenu an-Naseehah” three times, while in Sahih Muslim it is without repetition. When the Companions heard the importance and the significance of naseehah, and it’s great position, they said: “To whom O Messenger of Allah?” So the Prophet (ﷺ) answered with the five categories mentioned in the hadith. It was explained by the people of knowledge about the five. The best explanation is from Abu ‘Amru Ibn Solah in his book Sianatu Sahih Muslim min Ikhlal wal Ghalat, wa Himayatihi minal Isqat was Saqat:

An-Naseehah for Allah Tabaraka wa Ta’ala means: to proclaim His Oneness and to attribute Him with the perfect and magnificent attributes, to purify Him from whatever that is contrary and against perfection, to keep away from disobeying Him, to establish obedience and love towards Him with sincerity, to love and hate for His sake, to fight against disbelief and the likes for His sake, and to make dua and urge towards naseehah.

An-Naseehah for His Book (Al-Qur’an) means: to have Iman in it, to venerate and to purify it, to recite it with the proper recitation, to be aware of its commandments and prohibitions, to understand its sciences and parables, to contemplate on its verses, to make dua with it, to protect it from distortions of the extremists and defamations of the disbelievers.

An-Naseehah for His Messenger (ﷺ) is somewhat similar: to have Iman in him and in whatever he comes with, to venerate and dignify him, to adhere in obedience, to revive his Sunnah, to take guidance from his teachings and to propagate it, to take as enemy those whom he takes as enemy, to love whom so ever he loves, to follow his akhlak, to behave according to ethics, to love his family and companions, and so on.

An-Naseehah for the leaders of the Muslims means: to collaborate with them upon the truth and to obey them in it, to exhort and remind them with gentleness and kindness, to stay away from opposing them, to ask Allah to grant them at-Taufiq and diligent in it.

An-Naseehah for the rest of the Muslims (besides the leaders) means: to give guidance to them towards their well-being, to teach them their religion and worldly matters, to conceal their mistakes, to cover their fault, to help and protect them against their enemies, to keep away from deception and envy towards them, to love for them what a person like, to hate for them what a person dislike, and so on.”

Hadith

On the authority of Abu Sa’eed al-Khudree (may Allah be pleased with him), that the Messenger of Allah (peace and blessings of Allah be upon him) said:
There should be neither harming (darar) nor reciprocating harm (dirar). A hasan hadeeth related by Ibn Majah, ad-Daraqutnee and others as a musnad hadeeth.

On the authority of Abu Hurayrah (may Allah be pleased with him) who said:
I heard the Messenger of Allah (peace and blessings of Allah be upon him) say, “What I have forbidden for you, avoid. What I have ordered you [to do], do as much of it as you can. For verily, it was only the excessive questioning and their disagreeing with their Prophets that destroyed [the nations] who were before you.” [Al-Bukhari] [Muslim]

On the authority of Tameem ibn Aus ad-Daree (may Allah be pleased with him):
The Prophet (peace and blessings of Allah be upon him) said, “The deen (religion) is naseehah (advice, sincerity).” We said “To whom?” He (peace and blessings of Allah be upon him) said “To Allah, His Book, His Messenger, and to the leaders of the Muslims and their common folk.” [Muslim]

On the authority of Abdullah, the son of Umar ibn al-Khattab (may Allah be pleased with him), who said:

‘I heard the Messenger of Allah (peace and blessings of Allah be upon him) say, “Islam has been built on five [pillars]: testifying that there is no deity worthy of worship except Allah and that Muhammad is the Messenger of Allah, establishing the salah (prayer), paying the zakat (obligatory charity), making the hajj (pilgrimage) to the House, and fasting in Ramadhan.”’ [Al-Bukhari & Muslim]

It is narrated on the authority of Amirul Mu’minin, Abu Hafs ‘Umar bin al-Khattab, radiyallahu ‘anhu, who said:

I heard the Messenger of Allah, sallallahu ‘alayhi wasallam, say: “Actions are (judged) by motives (niyyah), so each man will have what he intended. Thus, he whose migration (hijrah) was to Allah and His Messenger, his migration is to Allah and His Messenger; but he whose migration was for some worldly thing he might gain, or for a wife he might marry, his migration is to that for which he migrated.” [Al-Bukhari & Muslim]

Prophet Muhammad (peace and blessings be upon him) said: “When you see the new moon of Dhul Hijjah, if any one of you wants to offer a sacrifice, then he should stop cutting his hair and nails until he has offered his sacrifice.” -Muslim

The Prophet (sallaAllahu ‘alayhi wasallam) said: “There are no days on which righteous deeds are more beloved to Allah than these ten days.” They said: “Not even jihad for the sake of Allah?” He said: “Not even jihad for the sake of Allah, unless a man goes out himself for jihad taking his wealth with him and does not come back with anything.” (Reported by Bukhari)